2008 Dodge Caliber SRT4

Same hot concept, chunky new package.

Aug 1, 2007

On the great scale of anticipation, the revival of the SRT4 may not rank quite as high as the countdown to a national election, but it scores way higher than the countdown to Barry Bonds hitting his 756th home run, or any Elvis sighting.

We know that you know what that SRT4 alphanumeric designation means, but for the sake of the few who may be playing catch-up, please indulge us in a moment of review.

SRT stands for Street and Racing Technology, and it describes a semisecret group of Chrysler performance zealots whose mission is to create limited-production sports cars, such as the Dodge Viper, or take ordinary production cars and make them go faster. Much faster.

The number—in this case, 4—designates the number of cylinders the SRT boys get to mine for more power. Much more.

The SRT4: Speed Past and Present

The previous SRT4 was based on the Dodge Neon, and its turbocharged 2.4-liter four delivered 230 horsepower and 250 pound-feet of torque—a tough act to follow. The new SRT4 is based on the Dodge Caliber—you already knew that, right?—and its 2.4-liter turbo four churns up 285 horsepower and 265 pound-feet of torque.

Those are some pretty hefty gains, and you'd expect to see some pretty impressive performance numbers to go with 'em. After all, the previous SRT4 was capable of scooting to 60 mph in 5.3 seconds and covering a quarter-mile in less than 14 seconds. So with an additional 55 horsepower, the Caliber SRT4 ought to be even quicker, right? Uh-oh, not so fast—or should we say not as fast? We're neglecting an important factor: mass.

That 5.3-second Neon-based SRT4 we tested three years and some months ago weighed 2984 pounds. Our Caliber SRT4 test car tipped the scales nearly 250 pounds heavier. This will produce inevitable consequences at the test track, and the '08 SRT4's 0-to-60-mph and quarter-mile times are bound to suffer. We predict a half-second penalty for each.

Still, 60 mph in six or so seconds is a long way from slow. Moreover, the car's broad power band makes short-yardage passing situations a snap, and it has a claimed top speed of 155 mph.

Boost Makes World Engines Happy

The starting point for the SRT4's punch is Chrysler's so-called world engine, a joint-venture (with Hyundai and Mitsubishi) 2.4-liter aluminum four and the top engine offered in the everyday Caliber. In base-Caliber tune, it delivers 172 horsepower and 165 pound-feet of torque.

What's the difference? In a word, turbocharging.

But of course there's more to it than just bolting on a 12-psi Mitsubishi TD04 turbocharger. There's also a big air-to-air intercooler. Cast aluminum pistons. Forged steel connecting rods. Variable valve timing. Exhaust valves made from Inconel high-temp alloy. Enhanced coolant flow. A high-flow fuel pump. An external oil cooler.

A six-speed Getrag manual transmission with short-shift throws and snick-snick engagements is the tool with which the driver effects gearchanges, and it's way better than the manual tranny offered in base Calibers.

A Lower Caliber

Alterations to the Caliber's suspension are at least as extensive as those made to the engine. Ride height is down 1.1 inches in front, 0.9 inch at the rear, with the fenders snugged down around 19-inch aluminum alloy wheels wearing 225/45R-19 Goodyear Eagle RS-A rubber as standard equipment. Same-size Goodyear F1 Supercars are optional.

Lowering the car serves three purposes. First, that hunkered-down look helps separate the SRT4 from the plebeian Caliber owned by the yoga instructor who lives next door. Second, it pulls the car's center of gravity toward the pavement. Third, and most important, it flattens the angle of the driving shafts between the differential and front wheels.

The objective of the latter is taming torque steer, the disconcerting tug to the right or left when the driver tramps on the gas. It's still a common affliction in small front-drive cars with big horsepower, and if the SRT4 isn't entirely cured, it's at least in partial remission.

More suspension revisions: The spring rates are higher, front and rear, with high-performance shocks at both ends. The result of all this tuning is a car that responds much more decisively than its humble non-SRT counterpart.

The downside is that the reduced suspension travel can produce some awkward gyrations in aggressive cornering, and the basic handling trait in hard use is understeer—the faster the driver pushes in a corner, the more the car resists. This, too, is common in front-drive cars.

Brakes Aren't Just for Stopping, You Know

The brakes are big, robust, and devoid of fade. And in addition to their normal function, they do double duty as a substitute for a limited-slip differential.

Huh? Brakes for a diff? Well, instead of a conventional limited-slip diff, Chrysler uses a brake-based system of the type also employed by BMW and Mercedes, among others. The function is simple: When the system sensors detect traction loss on one of the drive wheels, it applies the brake on that wheel to send power to the opposite side.

Although the system creates some strange sensations when the car is operating at its absolute limit, the SRT engineers insist it's more effective than the mechanical limited-slip differentials they sampled while the SRT4 was in gestation.

New Wrapper Looks the Part

It's important for an SRT hot rod to look the part. To that end, the Caliber SRT4 wears a revised front fascia with a deeper air dam and molded-in ducts for brake cooling. The Dodge crosshair grille shelters the intercooler, and the hood is distinguished by a functional air scoop and a pair of decorative vents. There's also an oversized parasol wing over the rear hatch and diffusers at the rear of the underbody to help optimize airflow beneath the car. The net effect is a Caliber that looks like it's spent a lot of quality time at the gym.

A very cool option is a small readout integrated with the fuel and coolant gauges that gives the driver all kinds of vital info—0-to-60-mph times, 1/8-mile time and speed, quarter-mile, lateral g-loading, braking distances, fuel economy, and more.

SRT4 pricing starts at five bucks shy of 23 grand, which is $60 more than the Mazdaspeed 3, another turbo-crazy hot hatch with similar performance capabilities. It sounds like a shootout is brewing.